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JerryscriptApplication

CVE-2020-29657

CRITICAL · 9.1 CVSS v3.1 Published 2020-12-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In JerryScript 2.3.0, there is an out-of-bounds read in main_print_unhandled_exception in the main-utils.c file.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

An out-of-bounds read vulnerability exists in JerryScript 2.3.0 within the main_print_unhandled_exception function in main-utils.c. This memory safety flaw could allow an attacker to read sensitive memory contents beyond allocated buffer boundaries, potentially leading to information disclosure.

MitigationUpgrade JerryScript to a version containing the security fix for this vulnerability. If immediate patching is not possible, minimize the exposure of the JavaScript engine to untrusted code and consider deploying additional sandboxing layers.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
JerryscriptApplication
Affected:= 2.3.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify JerryScript version
    Run jerry --version or check VERSION file in the build/installation directory, or inspect version.h/jerryscript.h for JERRY_VERSION_MAJOR and JERRY_VERSION_MINOR macros
    Affected if Version is exactly 2.3.0 (any build or commit matching this release)
  2. Confirm the vulnerable source file is present
    Locate main-utils.c in the source tree or binary; check if the binary includes the main_print_unhandled_exception function (use objdump, nm, or strings)
    Affected if The main-utils.c source file exists and the binary contains main_print_unhandled_exception symbol
  3. Determine if exception handling is used
    Review application code that uses JerryScript to see if it calls jerry_cleanup or uses any try-catch mechanisms that may trigger unhandled exception paths
    Affected if The JavaScript execution code can trigger unhandled exceptions that reach the vulnerable function

You are affected if the installed JerryScript version is exactly 2.3.0 and your application processes JavaScript that can produce unhandled exceptions.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade JerryScript to a version containing the security fix for this vulnerability. If immediate patching is not possible, minimize the exposure of the JavaScript engine to untrusted code and consider deploying additional sandboxing layers.

Fix this in Jerryscript Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-29657 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data